Synopsis: After a violent storm at sea,
the inert body of a man is found on the
beach near the Naval Undersea Center. But
this is no ordinary man. Equipped with
webbed hands and gills instead of lungs, he
can breathe underwater, swim faster than a
dolphin and dive to incredible depths. He is
nursed back to health by Doctor Elizabeth
Merrill and given the name Mark Harris. In
return Mark agrees to work for the
Foundation of Ocean Research and his first
assignment is to seek out a missing
submarine carrying top military officials.
Swimming to incredible depths, Mark
discovers an enormous undersea habitat
constructed by Mr. Schubert, a maniacal
scientist who plans to destroy all the
nations of the world with their own nuclear
weapons through an ingenious method of mind
control.